The element chromium is thought to be a cancer causing agent. Chromium in the form of the chromate ion in a water soluble compound presents a risk to humans. We can remove thi srisk by chemically reacting the chromate ion causing the formation of the highly insoluble chromium hydroxide. to do this the chromate containing compound is reacted with solid sodium ditiotite, in a basic environment, according to the skeletal ionic equation: CrO4(-2) (aq) + S2O4 (-2) (aq) {oh-} Cr(OH)3 (s) + SO3(2-) (aq) a. balance the equation in basic b. if 100.l of contaminated water with a concentration of chroate ion of 0.0148 M is to be treated by this method, what mass of sodium dithionate, Na2S2O4 is needed?